Electric switch



April 21, 1953 A. H. MIDGLEY 2,536,089

ELECTRIC SWITCH Filed Oct. 24, 1949 3 Sheets-Sheet 1 Max. AT\ON \NSULATION April 21, 1953 A. H. MIDGLEY 2,636,089

ELECTRIC SWITCH Filed 00;- 24, 1949 3 Sheets-Sheet 2 IN SULATKDN I271) zzimz April 21, 1953 A. H. MIDGLEY ELECTRIC SWITCH 5 Sheets-Sheet 3 Filed Oct. 24, 1949 IN SULAT\ON (N SUL A'T\ON- llzvzz if/ 0 l Patented Apr. 21, 1953 ELECTRIC SWITCH Albert Henry Midgley, Moor Park, N orthwood, England Application October 24, 1949, Serial No. 123,195 In Great Britain October 27, 1948 6 Claims.

This invention relates to electric switches particularly for use with traffic indicators on motor vehicles although it will be understood that the invention is not limited to this particular application.

Switches for traflic indicators are already known to be operated by clock-work mechanism in such a manner that, after a predetermined delay, the switch will automatically open and so render the indicator inoperative. 'Ihus, moving the switch to the left, for example, will close the circuit and cause the left-hand signal to be given, and after a predetermined period, the switch will automatically open the circuit. Similarly, when the switch is moved to the right, the right-hand signal will be given, and again the circuit will be automatically opened after the predetermined period of delay.

The present invention relates more particularly to such delay action switches and has for its object to improve the same by combining with the switch suitable means whereby the signal lights may be made to flash on and on at intervals during the period of delay for which the main circuit is closed.

More specifically the invention consists in a clock-work operated delay action electric switch in which a supplementary switch in the main circuit is periodically opened and closed by a cam driven from a suitable shaft in the clockwork train.

Further features of the invention will be apparent from the description given hereafter.

The accompanying drawings illustrate several modes of carrying out the invention.

Figure 1 is a rear view of one form of switch in accordance with the invention.

Figure 2 is a rear view with parts removed.

Figure 3 is a front view with the cover removed.

Figure 4 is a part sectional plan of the complete switch.

Figure 5 is a view of a detail.

Figures 6 and '7 are views showing two modifications.

In carrying my invention into eiiect in one convenient manner as, for example, in its application to a trafiic indicator switch on a motor vehicle, I may form my delay action switch as to its main characteristics, in any usual or suitable manner. In the particular construction shown in Figures 1 to 5, for example, the switch handle it operated by the driver is mounted upon a spindle b which carries a cam c by which the clock-work train of gears is set in motion, and

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also a rotary contact member d consisting of an inner metal sheet between two outer insulating sheets and associated with two switches e, f in the circuit of the respective traflic lights which may be arranged in the rear of the vehicle, and which, by their disposition and/or distinctive colouring (such as red and green) give the required indication of the drivers intention to the driver of any following vehicle. The cam c above referred to acts upon a spring-controlled lever 9 having a pin and slot connection with a lever h carrying a pawl i acting'on the first wheel is of the clock gear train incorporated in the switch, and the arrangement is such that by turning the switch handle a either to the right or to the left, the clock-work is set in motion, while in the first case the'right-hand signal lamp is lit, and in the second case the left-hand lamp is lit. After a predetermined interval the clock-- work comes to rest and the circuit is opened and the switch handle returned to neutral position.

The rotary contact member it above referred to is associated with a supplementary switch I in the main circuit, which switch embodies a spring arm 111. having a contact m adapted to co-operate with a fixed contact m the arrangement being such that when said contacts are separated, the main circuit is broken. In order that such separation may occur a number of times so that the light will flash on and off a number of times during the period of delay before the main circuit is finally broken, I connect a wheel is in the clock train by means of a sleeve with a toothed wheel n of insulating material and the teeth of which co-operate with a projection m on the spring arm m of the supplementary contact. The arrangement is such that, when the switch handle a is moved to one side or the other to close the main circuit, the clockwork is set in motion and the toothed cam Wheel n rotates so that its teeth ride under and engage the projection m causing the spring arm m to oscillate so that the contacts m, m are alternately made and broken and thus the main circuit is periodically broken and re-established, and the light flashes on and ofi.

In the modification shown in Figure 6 the first wheel of the clock-work train is connected by means of a sleeve to a second toothed wheel R the teeth of which co-operate with a pin 0' on a pivoted lever o, the free end of which carries an insulated projection 0 adapted to act on an extension of the supplementary spring arm m. In this construction, too, the supplementary switch embodies two moving contacts m co-opcrating with two fixed contacts m This duplication of contacts produces double the number of flashes that would be produced if only a pair of contacts were employed, and clearly the number of pairs of contacts could be still further increased to increase the speed of the flashing.

Figure 7 shows a form very similar to that of Figures 1 to 4 but with a slightly different form of rotary contact member 11 which is of insulating material and a slightly different arrangement of the switches e and f.

It will be understood that the invention xtends broadly to a delay action switch embodying means for periodically breaking the circuit during the period of delay, and the invention therefore is not to be confined to the particular application nor to the particular constructional details herein described and all of which ar merely by way of example to describe the nature of the invention and not to limit its scope.

: I claim: I

' 1. A delay action switch comprising a switch handle, a spindle adapted to be rotated by the switch handle, a clockwork train of gears adapted to be set in motion by the rotation of the spindle in one direction and by the rotation of the spindle in the opposite direction, a cam on said spindle, a switch adapted to be closed by said cam on rotation of the spindle in said one direction, a further switch adapted to be closed by said cam on rotation of the spindle in said opposite direction, and a supplementary switch adapted to be periodically opened and closed during the running down of the clockwork mechanism.

2. A delay action switch comprising a switch handle, a spindle adapted to be rotated by the switch handle, a clockwork adapted to be set in motion by the rotation of the spindle in one direction and by the rotation of the switch handle in the opposite direction, a cam on said spindle, a

switch adapted to be closed by said cam when the switch handle is operated in said one direction, a further switch adapted to be closed by said cam when the switch handle is operated in said opposite direction, a supplementary switch adapted to be periodically opened and closed during the running down of the clockwork mechanism, an insulated toothed wheel driven by the clockwork, a spring arm forming part of the supplementary switch, and a projection on the spring arm acted upon by the teeth of the insulated toothed wheel.

3. A delay action electric switch according to claim 1, in which the supplementary switch embodies a spring arm acted upon by an insulated pin carried by a lever having thereon a pin cooperating with a wheel driven by or formin part of the clockwork train.

4. A delay action switch according to claim 1, in which the supplementary switch embodies two sets of fixed and movable contacts to increase the rate of make and break.

5. A delay action switch as claimed in claim 2, v in which the toothed wheel is operated by the;

first wheel of the clockwork.

6. A delay action switch as claimed in claim 2, Y

in which the toothed wheel is operated by the second wheel of the clockwork.

ALBERT HENRY MIDGLEY. 

